In applicants co-pending patent application Ser. No. 09/020,107, the disclosure of which is herein incorporated by reference, a method is disclosed for preheating dental composite material within a container before extruding the material from the container into an oral cavity for clinical application. The dental composite material is preheated to an elevated temperature above that of ambient temperature just prior to placement into a prepared tooth in the oral cavity. The prepared tooth is then clinically treated by exposure to light radiation while the dental restorative composite material is at the elevated temperature. Conversely, at present, photocurable dental materials are extruded into the patients mouth at ambient temperature from a standard dispensing device and cured by exposure to light radiation at ambient temperature.
In accordance with the findings of the applicant and as taught in the aforementioned patent the physical properties of photocurable dental material(s) are enhanced when preheated just prior to clinical usage. Examples of dental materials which can be enhanced by preheating prior to use include restorative materials (commonly referred to as filling materials), etching agents, bleaching compositions, dental cements, impression materials and more particularly photocurable dental restorative materials.
Applicants application also teaches preheating one or more standard pre-filled computes of dental material using a small heating device capable of housing a plurality of pre-filled computes in a removable section of the device. The removable section acts as a heat sink for all of the computes permitting the removable section to be removed after being heated to an elevated temperature and placed close to the patient, preferably upon a standard bracket tray which most dentists presently use to hold instruments and medicaments, during a given operative procedure. Prior to use a heated compule is placed in a conventional dispenser by the dentist and dental material is then extruded directly into the prepared dental cavity.
Conventional dispensers are mechanical extruding devices such as is taught in U.S. Pat. No. 4,383,853 by Welsh and U.S. Pat. No. 5,489,207 by Dragon and have no other purpose. The dispenser of the present invention is a hand held portable device designed to heat a compule of dental material which is removably inserted in the dispenser to an elevated temperature above that of ambient and to controllably extrude the pre-heated dental material from the compule directly from the dispenser into an oral cavity for clinical application.
The present invention is directed to a dispenser for controllably heating a compule of dental material which is removably inserted into the dispenser and for extruding dental material from the compule. The compule has a circumferential flange at one end which surrounds a movable sealing plug and has a generally cylindrical body in which the dental material to be extruded is stored. The dispenser of the present invention comprises:
an elongated section having a front end and a rear end with said front end having a cavity adapted for the removable placement of said compule,
a plunger mounted for reciprocal movement within the elongated section of said dispenser in alignment with the cavity,
means in response to the control of an operator for advancing the plunger into engagement with said compule to express dental material from said compule;
a heating unit having a heating element located in the front end of said dispenser for heating substantially the entire compule in said cavity such that all or substantially all of the material in the compule is heated at one time;
a supply of electrical energy and
means for controlling the supply of electrical energy to said heating element in the heating unit. The means connected to the plunger can be a manually movable lever arm having one end connected to the plunger for controllably advancing the plunger into engagement with the compule to dispense dental material from the dispenser or a motorized control unit for automatically dispensing material in response to a command control signal from the operator. The motorized unit preferably including a lead screw and a gear box reducer to increase the output torque of the motor. For the embodiment in which the plunger is operated manually the movable lever should be spaced apart from the handle so that the lever and handle can be held in one hand by the operator of the dispenser and squeezed for controllably advancing the plunger as the lever moves relative to the handle. In the manually operated plunger embodiment the movable lever arm is preferably connected to the plunger by means of a rack and pinion mechanism.